1. Field of the Invention
Embodiments of the present invention relate to methods of forming integrated circuit packages having an LED molded into the package, and the integrated circuit package formed thereby.
2. Description of the Related Art
The strong growth in demand for portable consumer electronics is driving the need for high-capacity storage devices. Non-volatile semiconductor memory devices, such as flash memory storage cards, are becoming widely used to meet the ever-growing demands on digital information storage and exchange. Their portability, versatility and rugged design, along with their high reliability and large capacity, have made such memory devices ideal for use in a wide variety of electronic devices, including for example digital cameras, digital music players, video game consoles, PDAs and cellular telephones.
While a number of packaging configurations are known, flash memory storage cards may in general be fabricated as system-in-a-package (SiP) or multichip modules (MCM), where a plurality of dice are mounted on a substrate. The substrate may in general include a rigid base having a conductive layer etched on one or both sides. Electrical connections are formed between the dice and the conductive layer(s), and the conductive layer(s) provide an electric lead structure for integration of the dice into an electronic system. Once electrical connections between the dice and substrate are made, one or both sides of the assembly are then typically encased in a molding compound to provide a protective package.
In view of the small form factor requirements, as well as the fact that flash memory cards need to be removable and not permanently attached to a printed circuit board, such cards are often built of a land grid array (LGA) package. In an LGA package, the semiconductor die are electrically connected to exposed contact fingers formed on a lower surface of the package. External electrical connection with other electronic components on a host printed circuit board is accomplished by bringing the contact fingers into pressure contact with complementary electrical pads on the printed circuit board. LGA memory packages are ideal for flash memory cards in that they have a smaller profile and lower inductance than pin grid array (PGA) and ball grid array (BGA) packages.
Significant economies of scale are achieved by forming a plurality of integrated circuit (IC) packages at the same time on panels. In fabrication, the chips and other circuit components are mounted on the panel, which may be for example a substrate or leadframe, and molded in epoxy molding compound. Once fabricated, the IC packages are separated from the panel, and those which pass inspection may then be enclosed within an outer plastic lid to form a completed flash memory card.
After the molding process, it is known to physically and electrically attach a liquid crystal diode (LED) to a portion of the substrate outside of the molded package. In the finished flash memory, the LED may be illuminated by a controller within the IC package, for example to indicate when read/write operations are being performed on the flash memory. Conventionally, the LED is positioned outside of the molded package.